Generally, a computer system may have multiple operating systems. After the computer is powered on, the user may select a certain operating system from a list of operating systems, and the certain operating system is loaded into the computer system. Consequently, associated application programs may be executed under the environment of the certain operating system.
From the above discussions, the user needs to determine which operation system to be loaded during the startup of the computer system. After a certain operating system is selected, if the user wants to load another operating system, the computer system should be turned off and then the booting process should be performed again. After the computer system is booted again, the user may select another operating system from the list of operating systems. In other words, the process of restarting the computer system is the only way to switch between multiple operating systems of the computer system. However, this way to switch between the multiple operating systems is time-consuming.